The present invention relates to apparatus for dispensing documents such as banknotes or other documents of value piecemeal from a bundle of documents.
Known such apparatus comprises a bundle holder that includes a slide surface on which the bundle rests and is displaced forwards, a front wall, a pusher which pushes the bundle along the slide surface and into contact with the front wall, a dispensing roll of which a peripheral part is in contact with the foremost document in the bundle, drive means for selective rotation of the dispensing roll in a first direction, for dispensing said foremost document in the bundle in the plane of said document, a pair of rolls that have mutually parallel axles and that are adapted so that their barrel surfaces act on respective opposite sides of a document dispensed into the nip defined by said roll pair, wherein the rolls of said roll pair are rotated at different peripheral speeds so as to mutually separate any documents that may have been dispensed essentially simultaneously by the dispensing roll, a conveyor that receives documents passing through the roll pair and conveys said documents at a speed which is higher than the speed at which the documents pass through the roll pair, and a sensor that detects the arrival of the document in the conveyor.
One problem with arrangements of this kind is that the document separator is expensive, complex and wears relatively quickly. Known separators normally include a roll pair of which one roll is driven to drive the document into the conveyor, whereas the other roll is driven to provide a braking force of selected magnitude on a document advanced by the roll pair.
In accordance with the present invention, document dispensing apparatus comprises a document store having a document exit; a feed roller for feeding documents out of the document store through the document exit; and a separation system including a pair of juxtaposed rollers defining a nip to which documents are fed from the document store exit, and a drive motor coupled to one of the rollers to cause the one roller to rotate in a document feed direction, the one roller being drivingly coupled to the other roller of the pair via a one-way transmission such that drive is communicated to the other roller only when the one roller is driven in a direction opposite to the feed direction.
With this invention, the separation system has a much simpler construction than the prior art and is highly reliable while achieving even wear on the xe2x80x9cotherxe2x80x9d roller.
Preferably, the coefficient friction of the one roller is higher than that of the other roller. This enhances the separation process carried out by the separation system.
Conveniently, the apparatus further comprises a conveyor which receives a document passing between the pair of rollers, and which conveys the document at an elevated speed; a sensor for detecting the presence of a document at the inlet to the conveyor; and a control unit, the sensor being adapted to cause the control unit to influence the current supply to the drive motor when detecting the leading edge of said document, so as to reduce braking of a document passing through the roller pair and having entered the conveyor, to a selected level.
In the preferred arrangement, the drive motor may also be adapted to drive the feed roller. When the sensor detects that a document has been fed into the conveyor, it causes a computer connected thereto to change the supply of current to the motor so as to reduce the braking effect of the roller pair on the document. The conveyor engages a document before the document has left the roller nip, whereby the document is braked by virtue of the conveyor speed being greater than the conveying speed of the roller pair. When the sensor later detects the trailing edge of the document, the computer is caused to drive the motor in the reverse direction for a short period of time, for instance for some milliseconds. The second transmission then jogs the second roller of said roller pair into rotation, preferably in a direction which is opposite to the direction in which the document passes through the roller nip. Consequently, after each separation operation, the second roller of the roller pair will rotate to advance a fresh peripheral section for coaction with a document and the barrel surface of the first roller of said roller pair respectively.
The transmission between the first and second rollers of the roller pair may include mutually coacting gearwheels disposed coaxial with the rollers of said roller pairs or alternatively a drive belt and one-way clutch could be used. The second roller of the roller pair is preferably suitably spring-biased in a direction towards the first roller of the roller pair. For example, the second roller of said roller pair may have a central shaft shank that is guided in chassis slots for movements in a normal direction to the documents passing through the roller pair.